In the jungles of Vietnam, biologists Dr Joachim Bresseel and Dr Jerome Constant from Royal Belgian Institute of Natural Sciences have discovered two new species and one new subspecies of Phasmatodea, an order of insects whose members are known as stick insects.
The latter, named Phryganistria heusii yentuensis, is the second-longest insect known to date.
The current record-holder is another stick-insect called Phobaeticus chani. It is found on the Indonesian island of Borneo and measures a huge 36 cm in length.
According to the team, Phryganistria heusii yentuensis is “currently recorded from Tay Yen Tu Nature Reserve located in Luc Nam and Son Dong Districts, Bac Giang Province, about 150 km ENE of Hanoi. Another specimen is also reported from northeast Vietnam: Mount Mauson, 30 km E of Lang Son city.”
The other two newfound species are Phobaeticus trui and Phryganistria tamdaoensis.
Stick insects first appeared in the fossil record over 40 million years ago and are related to cockroaches, mantids and, more distantly, the grasshoppers and crickets.
There are around 3,000 known species, mainly living in the tropics and subtropics where some species may be up to 30 cm in length.
They are slow-moving insects, a behavior pattern that is consistent with their cryptic lifestyle. When discovered they will often drop to the ground and remain motionless rather than take flight. Some species will also shed legs when attacked, growing them back over time.
All stick insects are herbivores as both adults and nymphs feeding on the leaves of trees and shrubs.
